The 23-year-old had been available on a free transfer for a short space of time following his decision not to transfer his contract over to Rangers newco.
Having managed the winger during the pair's stint together at Birmingham City, Hull boss Steve Bruce has moved quickly to reunite himself with the Nigerian international.
"Hull City have completed the signing of Sone Aluko," read a statement on the club's official website.
"The 23-year-old, who can operate in midfield, out wide and up front, has put pen to paper on a two-year deal with the club."
Aluko has also played for Scottish Premier League side Aberdeen.